How to get kernel to recognize added CPU?

[Jared Middleton]

Server:
Compaq ProLiant DL380 G3
1 Intel Xeon 2.4GHz CPU
Red Hat Linux 7.3 Professional
kernel: 2.4.20-20.7

Just added a second matching 2.4GHz CPU. Upon cold boot, the system BIOS immediately recognized the additional CPU, but linux does not seem to.

I downloaded the latest SMP kernel from Red Hat (2.4.20-20.7smp), installed the RPM, modified GRUB to use it, and rebooted.

However, "top" does not show the new CPU.

$ uname -a
Linux myserv 2.4.20-20.7smp #1 SMP Mon Aug 18 14:46:14 EDT 2003 i686 unknown

I'm not sure what needs to be tweaked.
Any help would be appreciated.

[Jerome Henry · Accepted solution]

Hi,

Check your BIOS :
1. Press F10 when the server boots to enter the System Configuration Utility
2. Press Enter to dismiss the splash screen
3. Immediately press CTRL+A
4. A message will appear informing you that you are now in "Advanced Mode"
5. Then select "Configure Hardware" -> "View / Edit details"
6. You will then see the advanced settings (intermixed with the ordinary ones)
7. Stroll down to "APIC Mode" and then select "Fully Mapped"
8. Save changes and reboot
9. Tell us...

hth

J

[Jared Middleton]

Although the details varied ever so slightly, Jerome's answer was right on (and something I should have remembered - DOH!).

Resolved by setting BIOS as follows...

Advanced Settings, MPS Table Mode:
Full Table APIC <- correct for SMP
Full Table Mapped
Disabled <- was set here before
Auto Set Table

Since the CPU's are hyperthreaded, "top" now shows 4 CPU's.

Thanks again.

-Jared

[Jerome Henry]

Glad it worked !

Sorry for the imprecision on the process. I do not have this machine, had to rely on HP online manual, which is quite imprecise about BIOS setup !

J